Techniques described herein may be applied to various wireless access systems such as code division multiple access (CDMA), frequency division multiple access (FDMA), time division multiple access (TDMA), orthogonal frequency division multiple access (OFDMA), single carrier frequency division multiple access (SC-FDMA), etc. CDMA may be embodied by radio technology such as universal terrestrial radio access (UTRA) or CDMA2000. TDMA may be embodied by radio technology such as global system for mobile communications (GSM)/general packet radio service (GPRS)/enhanced data rates for GSM evolution (EDGE). OFDMA may be embodied by radio technology such as IEEE 802.11 (Wi-Fi), IEEE 802.16 (WiMAX), IEEE 802-20, evolved UTRA (E-UTRA), etc. UTRA is a part of universal mobile telecommunications system (UMTS). 3rd generation partnership project (3GPP) long-term evolution (LTE) is a part of evolved UMTS (E-UMTS) using E-UTRA and employs OFDMA in downlink and SC-FDMA in uplink. LTE-advanced (LTE-A) is an evolved version of 3GPP LTE.